# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""Dark matter spectra."""
import numpy as np
import astropy.units as u
from astropy.table import Table
from gammapy.maps import Map, MapAxis, RegionGeom
from gammapy.modeling import Parameter
from gammapy.modeling.models import SpectralModel, TemplateNDSpectralModel
from gammapy.utils.scripts import make_path
from gammapy.utils.table import table_map_columns
import warnings
__all__ = [
"PrimaryFlux",
"DarkMatterAnnihilationSpectralModel",
"DarkMatterDecaySpectralModel",
]
[docs]
class PrimaryFlux(TemplateNDSpectralModel):
"""DM-annihilation gamma-ray spectra.
Based on the precomputed models of PPPC4 DM ID by [1]_, [2]_ and CosmiXs by [3]_, [4]_.
All available annihilation channels can be found there. The dark matter mass will be set
to the nearest available value. The spectra will be available as
`~gammapy.modeling.models.TemplateNDSpectralModel` for a chosen dark matter mass and
annihilation channel. Using a `~gammapy.modeling.models.TemplateNDSpectralModel`
allows the interpolation between different dark matter masses.
Parameters
----------
mDM : `~astropy.units.Quantity`
Dark matter particle mass as rest mass energy.
channel : str
Annihilation channel. List available channels with `~gammapy.astro.darkmatter.PrimaryFlux.allowed_channels`.
source : {"cosmixs", "pppc4"}, optional
Data source for the spectra. Default is 'pppc4'.
References
----------
.. [1] `Marco et al. (2011), "PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection" <https://ui.adsabs.harvard.edu/abs/2011JCAP...03..051C>`_
.. [2] `Cirelli et al. (2016), "PPPC 4 DM ID: A Poor Particle Physicist Cookbook for Dark Matter Indirect Detection" <http://www.marcocirelli.net/PPPC4DMID.html>`_
.. [3] `Arina et al. (2024), "CosmiXs: Cosmic messenger spectra for indirect dark matter searches" <https://arxiv.org/abs/2312.01153>`_
.. [4] `Di Mauro et al. (2025), "Nailing down the theoretical uncertainties of Dbar spectrum produced from dark matter" <https://arxiv.org/abs/2411.04815>`_
"""
channel_registry = {
"eL": "eL",
"eR": "eR",
"e": "e",
"muL": r"\[Mu]L",
"muR": r"\[Mu]R",
"mu": r"\[Mu]",
"tauL": r"\[Tau]L",
"tauR": r"\[Tau]R",
"tau": r"\[Tau]",
"q": "q",
"c": "c",
"b": "b",
"t": "t",
"WL": "WL",
"WT": "WT",
"W": "W",
"ZL": "ZL",
"ZT": "ZT",
"Z": "Z",
"g": "g",
"gamma": r"\[Gamma]",
"h": "h",
"nu_e": r"\[Nu]e",
"nu_mu": r"\[Nu]\[Mu]",
"nu_tau": r"\[Nu]\[Tau]",
"V->e": "V->e",
"V->mu": r"V->\[Mu]",
"V->tau": r"V->\[Tau]",
"aZ": "aZ",
"HZ": "HZ",
"d": "d",
"u": "u",
"s": "s",
}
mapping_dict_PPPC4_to_CosmiXs = {
"DM": "mDM",
"Log10[x]": "Log[10,x]",
"dNdLog10x[eL]": "eL",
"dNdLog10x[eR]": "eR",
"dNdLog10x[e]": "e",
"dNdLog10x[muL]": "\\[Mu]L",
"dNdLog10x[muR]": "\\[Mu]R",
"dNdLog10x[mu]": "\\[Mu]",
"dNdLog10x[tauL]": "\\[Tau]L",
"dNdLog10x[tauR]": "\\[Tau]R",
"dNdLog10x[tau]": "\\[Tau]",
"dNdLog10x[nue]": "\\[Nu]e",
"dNdLog10x[numu]": "\\[Nu]\\[Mu]",
"dNdLog10x[nutau]": "\\[Nu]\\[Tau]",
"dNdLog10x[u]": "u", # Does not exist explicitly on PPPC4, but it is equivalent to q
"dNdLog10x[d]": "d", # Does not exist explicitly on PPPC4, but it is equivalent to q
"dNdLog10x[s]": "s", # Does not exist explicitly on PPPC4, but it is equivalent to q
"dNdLog10x[c]": "c",
"dNdLog10x[b]": "b",
"dNdLog10x[t]": "t",
"dNdLog10x[a]": "\\[Gamma]",
"dNdLog10x[g]": "g",
"dNdLog10x[W]": "W",
"dNdLog10x[WL]": "WL",
"dNdLog10x[WT]": "WT",
"dNdLog10x[Z]": "Z",
"dNdLog10x[ZL]": "ZL",
"dNdLog10x[ZT]": "ZT",
"dNdLog10x[H]": "h",
"dNdLog10x[aZ]": None, # Does not exist on PPPC4
"dNdLog10x[HZ]": None, # Does not exist on PPPC4
}
tag = ["PrimaryFlux", "dm-pf"]
[docs]
def __init__(self, mDM, channel, source="pppc4"):
if source is None:
source = "pppc4"
warnings.warn(
"\nSince no spectra source has been chosen, PPPC4 will be used by default.\n",
UserWarning,
)
self.source = source.lower()
if self.source == "pppc4":
table_filename = (
"$GAMMAPY_DATA/dark_matter_spectra/PPPC4DMID/AtProduction_gammas.dat"
)
elif self.source == "cosmixs":
table_filename = (
"$GAMMAPY_DATA/dark_matter_spectra/cosmixs/AtProduction-Gamma.dat"
)
else:
raise ValueError(
"\n\nData source is not valid, please choose between PPPC4 or cosmixs\n"
)
self.table_path = make_path(table_filename)
if not self.table_path.exists():
raise FileNotFoundError(
f"\n\nFile not found: {table_filename}\n"
"You may download the dataset needed with the following command:\n"
"gammapy download datasets --src dark_matter_spectra"
)
else:
ascii_format = (
"ascii.commented_header"
if self.source == "cosmixs"
else "ascii.fast_basic"
)
self.table = Table.read(
str(self.table_path),
format=ascii_format,
guess=False,
delimiter=" ",
)
if self.source == "cosmixs":
self.table = table_map_columns(
self.table, self.mapping_dict_PPPC4_to_CosmiXs
)
self.channel = channel
# create RegionNDMap for channel
masses = np.unique(self.table["mDM"])
log10x = np.unique(self.table["Log[10,x]"])
mass_axis = MapAxis.from_nodes(masses, name="mass", interp="log", unit="GeV")
log10x_axis = MapAxis.from_nodes(log10x, name="energy_true")
channel_name = self.channel_registry[self.channel]
geom = RegionGeom(region=None, axes=[log10x_axis, mass_axis])
region_map = Map.from_geom(
geom=geom, data=self.table[channel_name].reshape(geom.data_shape)
)
interp_kwargs = {"extrapolate": True, "fill_value": 0, "values_scale": "lin"}
super().__init__(region_map, interp_kwargs=interp_kwargs)
self.mDM = mDM
self.mass.frozen = True
@property
def mDM(self):
"""Dark matter mass."""
return u.Quantity(self.mass.value, "GeV")
@mDM.setter
def mDM(self, mDM):
unit = self.mass.unit
_mDM = u.Quantity(mDM).to(unit)
_mDM_val = _mDM.to_value(unit)
min_mass = u.Quantity(self.mass.min, unit)
max_mass = u.Quantity(self.mass.max, unit)
if _mDM_val < self.mass.min or _mDM_val > self.mass.max:
raise ValueError(
f"The mass {_mDM} is out of the bounds of the model. Please choose a mass between {min_mass} < `mDM` < {max_mass}"
)
self.mass.value = _mDM_val
@property
def allowed_channels(self):
"""List of allowed annihilation channels."""
return list(self.channel_registry.keys())
@property
def channel(self):
"""Annihilation channel as a string."""
return self._channel
@channel.setter
def channel(self, channel):
if channel not in self.allowed_channels:
raise ValueError(
f"Invalid channel: {channel}\nAvailable: {self.allowed_channels}\n"
)
else:
if self.source == "pppc4":
if channel in ("aZ", "HZ"):
raise ValueError(
f"\n\nThe channel {channel} is not available in PPPC4, please choose another channel or use CosmiXs (cosmixs) as source\n"
)
elif channel in ("d", "u", "s"):
raise ValueError(
f"\n\nThe channel {channel} is not available in PPPC4, please choose the equivalent channel q or use CosmiXs (cosmixs) as source\n"
)
else:
self._channel = channel
elif self.source == "cosmixs":
if channel in ("V->e", "V->mu", "V->tau"):
raise ValueError(
f"\n\nThe channel {channel} is not available in CosmiXs, please choose another channel or use PPPC4 as source\n"
)
elif channel == "q":
raise ValueError(
"\n\nThe channel q is not available in cosmixs, please choose an equivalent channel such as d, u or s or use PPPC4 as source\n"
)
else:
self._channel = channel
[docs]
def evaluate(self, energy, *args):
"""Evaluate the primary flux."""
args = list(args)
args.append(self.mDM)
log10x = np.log10(energy / self.mDM)
dN_dlogx = super().evaluate(log10x, *args)
dN_dE = dN_dlogx / (energy * np.log(10))
return dN_dE
[docs]
class DarkMatterAnnihilationSpectralModel(SpectralModel):
r"""Dark matter annihilation spectral model.
The gamma-ray flux is computed as follows:
.. math::
\frac{\mathrm d \phi}{\mathrm d E} =
\frac{\langle \sigma\nu \rangle}{4\pi k m^2_{\mathrm{DM}}}
\frac{\mathrm d N}{\mathrm dE} \times J(\Delta\Omega)
Parameters
----------
mass : `~astropy.units.Quantity`
Dark matter mass.
channel : str
Annihilation channel for `~gammapy.astro.darkmatter.PrimaryFlux`, e.g. "b" for "bbar".
See `PrimaryFlux.channel_registry` for more.
scale : float
Scale parameter for model fitting.
jfactor : `~astropy.units.Quantity`
Integrated J-Factor needed when `~gammapy.modeling.models.PointSpatialModel`
is used.
z : float, optional
Redshift value. Default is 0.
k : int, optional
Type of dark matter particle (k:2 Majorana, k:4 Dirac). Default is 2.
source : {"cosmixs", "pppc4"}, optional
Data source for the spectra. Default is 'pppc4'.
Examples
--------
This is how to instantiate a `DarkMatterAnnihilationSpectralModel` model::
>>> import astropy.units as u
>>> from gammapy.astro.darkmatter import DarkMatterAnnihilationSpectralModel
>>> channel = "b"
>>> massDM = 5000*u.Unit("GeV")
>>> jfactor = 3.41e19 * u.Unit("GeV2 cm-5")
>>> modelDM = DarkMatterAnnihilationSpectralModel(mass=massDM, channel=channel, jfactor=jfactor) # noqa: E501
References
----------
`Marco et al. (2011), "PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection" <https://ui.adsabs.harvard.edu/abs/2011JCAP...03..051C>`_
"""
THERMAL_RELIC_CROSS_SECTION = 3e-26 * u.Unit("cm3 s-1")
"""Thermally averaged annihilation cross-section"""
scale = Parameter(
"scale",
1,
unit="",
interp="log",
)
tag = ["DarkMatterAnnihilationSpectralModel", "dm-annihilation"]
[docs]
def __init__(
self, mass, channel, scale=scale.quantity, jfactor=1, z=0, k=2, source="pppc4"
):
self.k = k
self.z = z
self.mass = u.Quantity(mass)
self.channel = channel
self.jfactor = u.Quantity(jfactor)
self.primary_flux = PrimaryFlux(mass, channel=self.channel, source=source)
self.source = source
super().__init__(scale=scale)
[docs]
def evaluate(self, energy, scale):
"""Evaluate dark matter annihilation model."""
flux = (
scale
* self.jfactor
* self.THERMAL_RELIC_CROSS_SECTION
* self.primary_flux(energy=energy * (1 + self.z))
/ self.k
/ self.mass
/ self.mass
/ (4 * np.pi)
)
return flux
[docs]
def to_dict(self, full_output=False):
"""Convert to dictionary."""
data = super().to_dict(full_output=full_output)
data["spectral"]["channel"] = self.channel
data["spectral"]["mass"] = self.mass.to_string()
data["spectral"]["jfactor"] = self.jfactor.to_string()
data["spectral"]["z"] = self.z
data["spectral"]["k"] = self.k
data["spectral"]["source"] = self.source
return data
[docs]
@classmethod
def from_dict(cls, data):
"""Create spectral model from a dictionary.
Parameters
----------
data : dict
Dictionary with model data.
Returns
-------
model : `DarkMatterAnnihilationSpectralModel`
Dark matter annihilation spectral model.
"""
data = data["spectral"]
data.pop("type")
parameters = data.pop("parameters")
scale = [p["value"] for p in parameters if p["name"] == "scale"][0]
return cls(scale=scale, **data)
[docs]
class DarkMatterDecaySpectralModel(SpectralModel):
r"""Dark matter decay spectral model.
The gamma-ray flux is computed as follows:
.. math::
\frac{\mathrm d \phi}{\mathrm d E} =
\frac{\Gamma}{4\pi m_{\mathrm{DM}}}
\frac{\mathrm d N}{\mathrm dE} \times J(\Delta\Omega)
Parameters
----------
mass : `~astropy.units.Quantity`
Dark matter mass.
channel : str
Decay channel for `~gammapy.astro.darkmatter.PrimaryFlux`, e.g. "b" for "bbar".
See `PrimaryFlux.channel_registry` for more.
scale : float
Scale parameter for model fitting
jfactor : `~astropy.units.Quantity`
Integrated J-Factor needed when `~gammapy.modeling.models.PointSpatialModel`
is used.
z : float, optional
Redshift value. Default is 0.
source : {"cosmixs", "pppc4"}, optional
Data source for the spectra. Default is 'pppc4'.
Examples
--------
This is how to instantiate a `DarkMatterDecaySpectralModel` model::
>>> import astropy.units as u
>>> from gammapy.astro.darkmatter import DarkMatterDecaySpectralModel
>>> channel = "b"
>>> massDM = 5000*u.Unit("GeV")
>>> jfactor = 3.41e19 * u.Unit("GeV cm-2")
>>> modelDM = DarkMatterDecaySpectralModel(mass=massDM, channel=channel, jfactor=jfactor) # noqa: E501
References
----------
`Marco et al. (2011), "PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection" <https://ui.adsabs.harvard.edu/abs/2011JCAP...03..051C>`_
"""
LIFETIME_AGE_OF_UNIVERSE = 4.3e17 * u.Unit("s")
"""Use age of univserse as lifetime"""
scale = Parameter(
"scale",
1,
unit="",
interp="log",
)
tag = ["DarkMatterDecaySpectralModel", "dm-decay"]
[docs]
def __init__(
self, mass, channel, scale=scale.quantity, jfactor=1, z=0, source="pppc4"
):
self.z = z
self.mass = u.Quantity(mass)
self.channel = channel
self.jfactor = u.Quantity(jfactor)
self.primary_flux = PrimaryFlux(
self.mass / 2, channel=self.channel, source=source
)
self.source = source
super().__init__(scale=scale)
[docs]
def evaluate(self, energy, scale):
"""Evaluate dark matter decay model."""
flux = (
scale
* self.jfactor
* self.primary_flux(energy=energy * (1 + self.z))
/ self.LIFETIME_AGE_OF_UNIVERSE
/ self.mass
/ (4 * np.pi)
)
return flux
[docs]
def to_dict(self, full_output=False):
data = super().to_dict(full_output=full_output)
data["spectral"]["channel"] = self.channel
data["spectral"]["mass"] = self.mass.to_string()
data["spectral"]["jfactor"] = self.jfactor.to_string()
data["spectral"]["z"] = self.z
data["spectral"]["source"] = self.source
return data
[docs]
@classmethod
def from_dict(cls, data):
"""Create spectral model from dictionary.
Parameters
----------
data : dict
Dictionary with model data.
Returns
-------
model : `DarkMatterDecaySpectralModel`
Dark matter decay spectral model.
"""
data = data["spectral"]
data.pop("type")
parameters = data.pop("parameters")
scale = [p["value"] for p in parameters if p["name"] == "scale"][0]
return cls(scale=scale, **data)
